Gas or vapor electric apparatus.



P. H. THOMAS.

GAS 0R VAPOR ELECTRIC APPARATUS.

. APPLICATION FILED SEPT. 12. l9l2. 1,156 Patented Oct. 12, 1915.

2 SHEETS$HEETI IIVVEAITOR WITNESSES ATTORNEYS P. H. THOMAS. GAS 0R VAPOR ELECTRIC APPARATUS.

APPLICATION FILED SEPT-12. 1912.

1,156,825., Patented Oct. 12, 1915.

2 SHEETS-SHEET 2.

WITNESSES ATTORNEYS PERCY H. THOMAS, or UPPER MoNTcLAm, NEW JERSEY, ASSIGNOR To COOPER HEWITT ELECTRIC COMPANY, or HOBOKEN', NEW JERSEY, A CORPORATION OF NEW JERSEY.

- Application filed September To all whom it may concern:

' Be it known that'I, PERCY H. THOMAS, a citizen of the United States, and resident of Upper Montclair, county of Essex, State of New Jersey, have invented certain new and lamps are characterized by tightly sealed envelops containing mercury and exhausted of .air and other foreign gases. Such lamps have peculiar characteristics of their own. When the mercury constituting the electrodes is cold, the pressure of mercury vapor is small and a very low voltage is-suflicient to support the flow of current when once started, although a high resistance to starting of current flow exists, as is well known. As the apparatus warms up the electrodes become hotter and the pressure of' the mercury vapor within the container is higher andv the operating voltage rises, while the starting resistance becomes less.

Thus the temperature at which the lamp finally steadies will be determined by the relative effectiveness of the heating and cooling means in the device as a whole, but more particularly as these, elements effect the temperature of the mercury electrodes. Since the heating effect will vary with change of circuit voltages and to a certain extent with change of airtemperatures, drafts, etc., the actual operating temperature of the lamp is likely to vary from time to time. This change in operating temperaturewill cause a considerable corresponding change in pressure and yoltage. i

One object of my inventionis to mnumlze these changes, as will be pointed out.-

' In the drawings Figures 1 and 2 represent different views of a self regulating lamp, Fig. 3 a different view and a supply circuit, and Fig. 4 shows another form 'of lamp adaptedto start without movement of the container and Fig. 5 amodification."

Fig. 6 shows a circuit for utilizinglamps of the character here proposed.

Figs.'1,' 2 and how the lamp in the Specification of Letters Patent.

Patented Uct. 12, 1915.

12,1912. Serial No. 719,923.

non-operating position. The lamp is composed of a tight container, having elec-- trodes 6 and 7, a V shaped light giving portion 1, two condensing chambers 2,2 and a body of mercury 8, 8 serving to fill the elec- Y substances, for example any kind of glass that will stand the temperature at which the lamp is to'run. When the lamp is to run at relatively high temperatures quartz may be used. The operation of this lamp is as follows. When the lamp isin the position shown in Fig. 1, voltage is applied to the terminals and the lamp tipped into the position shown in Fig. 2. The separation of the mercury into two parts in the V shaped portion, when current is passing, overcomes the starting resistance of the lamp and the flow is established in the vapor path. The I mercury will now stand at the same height in the chambers 2, 2 and in the V portion 1, but as the lamp heats up from the current flow, the pressure in the V portion will become the higher and the mercury will, rise in the'chambers 2, 2 until finally as the lamp reaches normal temperature, the level of the mercury in the V portion will be level with the opening into the chambers 8 or even below this point. Now any further increasing of the pressure in the V portion will causevapor to escape from this portion into the chambers 2, 2 where it will be-condensed and thus in effect will-greatly in-;

crease the cooling surface, for up to this point the chambers 2, 2 have acted only at a great disadvantage in cooling' the electrodes. It is clear that with this adjustment once the point of escape of the va or has been reached that even a considera le increase in the amount of heat generated, as by an. increase in the supply voltage or current will not be able to increase the internal pressure in the lamp and the voltage absorbed therein. This is very important j when-lamps are run in series circuits for if one lamp of a series tends from structural variations or other particular local conditionsto take a higher temperature than the others, its pressure will rise over theirs and this will in turn increase its heat loss and cause a further generation of excess heat and a greater rise of temperature and so on until the lamp goes out from excessive voltage or the whole series receives .too little current. This. is particularly important 111 this type of lamp because the lamps have a characteristic tending to show a constant current for all voltages. lamp as connected in such a series circuit, 10 being a source of constant current and 11 being other series devices, as for example other lamps like that already described herein.

Fig. 4 shows a device adapted to be started without the movement of the container.

In this lamp, 17 is. the light giving portion;

2, 2, are two chambers at the ends of the tube, the whole being hermetically closed.

a 6 and 7 are two starting electrodes and 18 is an additional connection adapted to cut out the heating coil 15 after starting. In

which force the mercury to fill the tube 17 completely or at least so that the circuit is completed therethrough. When the gener- 6 thus cutting out the starting coil 15. The regulation of this apparatus on varying the generator again.

ator 19 is excited a current flows through the coil 15, the electrode 6, through the mercury path in the tube 17, through the electrode 7 back th'roughthe other series devices 20, to When the coil 15 is sufiiciently hot, the mercury in the pocket 14 will vaporize to some extent which will cause a' bubble to appear at the top of the tube 17 ,thereby separating the mercury into two parts. This separation will start aflow of current to the vapor path which flow of current will heat the electrodes, increase the separation between the mercury columns in the tube 17 and finally force it down until at the equilibrium point vapor begins its escape from'the' tube 17 into the chambers 2, 2, which will be the stopping point of the increase. in pressure as has already been pointed out in connection with Figs. 1," 2.and 3. Meanwhile the mercury in being pressed back from the tube 17 is simultaneously connected to the electrode 18 and the electrode voltages and temperature conditions is S1m1- larto that of Figsfl, 2 and 3. Should it be I have shown this necessary in further controlling the pressure regulating features of either of these lamps, cont-actions or other means of checking the transfer of heat from the mercury electrode surface from the tube v17 to thechambers 1 may be employed. For example, a float such as the float 9 can be used for the purpose. Obviously, if the heat is not conveyed in material quantities through conduction from the tube 17 to the'mercury 25 in the cham her 2 before vapor begins to escape from the tube 17 a more sharply defined limit to the.

maximum pressure attainable will be secured.

In Fig. 5 I show a modification of the apparatus of Fig. 4, wherein direct atmospheric pressure is admitted to each chamber 2, 2 at the top through the porous plug 13 set in the outlet 12. This plug while admitting the passage of air under pressure will serve to restrain the mercury itself from escaping from the bulb. If asuitably purified mercury be used in this device and if the container be properly treated beforehand to move occluded gas this device may be put in operation without special pumping.

Fig. 6 shows a constant potential circuit adapted to supply lamps of the character described in this application. These may be run either single across the mains from the constant potential generator 23 as at 21 or two or more in a series group as shown at 22. The lamp shown in the present invention is adapted for use on either alternating or direct current. When used on alternating currentit is desirable that in the device of Fig. 4 the coil 15 heat the top of'the mercury columns in the tube 17 to a very considerable temperature before starting the actual flow of current in the vapor.

It is understood that while the devices shown have, been described as lamps this invention is applicable to other forms of ap: paratus and applicant wishes to cover his inventions in its broadest aspects.

Other materials than mercury may be used for the electrode material, it being essential, however, to most of these lamps that the electrode material be liquid.

I claim as my invention: a

1. A mercury vapor lamp comprising a W-shaped container, the central portion constituting a light giving-path and the end portions enlarged to act as condensing chambers, mercury in the lower portions of said container acting as electrodes and as seals between the center portion and the end portions in the non-operating and in the subnormal condition of the lamp, said end portions acting as condensing chambers during the steadying operations when the 1 mercury vapor pressure in the central portion of the condenser causes an escape of vapor to said condensing chambers.

2. In a vapor apparatuspsteadying means ing surface normally closed from said mainportion, in combination with means responslve to pressure above normal 1n the operatmg portion permitting escape of vapor from the operating portion to the supplementary condensing surface.

3. A vapor device, comprising three parts, namely, a central portion containing mercury and two condensing chambers, and means including a W shaped container and pivoting means permitting movement of the container to separate the mercury in said central portion into two electrodes and thereafter to enable vapor to escape from said central portion to the condensing chambers on any excess of pressure above a definite minimum. p

4. The method of regulating the vapor pressure in the vapor path of a high pressure mercury vapor apparatus, which consists in utilizing the excess mercury vapor pressure accompanying an abnormal rise in r the temperature of the lamp to open a free passage forthe escapeof the mercury vapor into a fresh condensing space;

5, A mercury vapor'app'aratus comprising a sealed container exhausted to a high I degree of purity and a central light-giving portion normally filled with mercury in the non-operating position, and means for utilizing outwardlyv generated heat to establish a vapor path in said central portion and inwardly generated pressure to limit the further development of said pressure but only when a certain predetermined minimum is reached.

6. A mercury vapor device comprising a main operating chamber and supplemental cooling means, said cooling means being normally inoperative in combination with means responsive only to a pressure in said main chamber greater thannormal for rendering operative said supplemental cooling means. I

Signed at New York, in the county of New York, and State of New York, this 9th day of September, A. D. 1912.

PERCY H. THOMAS.

Witnesses:

WM. H. CAPEL, THos. H. BROWN. 

